Telephone



May 1, 1928.

A. SCHWARTZ TELEPHONE Filed Jan. 21, 1927 INVENTOR:

ALar-zm- Scuwamz ATTORNEY.

Patented May 1, 1928.

fPA IiEN'T OFF I C E I ALBERT SCHWARTZ, OF NEW YORK, N. Y.

TELEPHONE.

- Application filedj'anuarvfl, 1927. Serial No. 162,592.

; This invention relates ,to a-novel device for silencing the voice of, the speaker in. tele-' cphonetransmitters to prevent LlIlilUtllOllZGd,

persons from hearing a conversation.

Tlnsdevmeis a sound deaden ng casing mounted over. the telephone,Inouth-pieceand is provided with .an. opening ,in front there- .of which.closelyrfits the lips of-theispeaker.

I On of theffeat r s of h s-inventionreend that the devicamay be more sanitary and to completely eliminate the possibility of spreadingdisease. The ventilating means .may include easily controllable doors. which while ,normally closed may. be opened at: 1ntervals to permit a freshcurrent ofair to circulate through 1 the interionof the. casing. The doorsthemselves may act as fans when quickly operated. When the doors are closed,"

however, the casing is practically airtight and since the mouth of the speaker closes the front opening it is impossible for the sound waves to escape to the exterior of the casing.

The present device is also suitable for use in noisy places, such as machine shops and busy streets, since no foreign noises may reach the vibrating membrane of the telephone transmitter.

It will be understood that the ventilating mechanism herein disclosed is only illustrative of the invention since the essence of the present invention is to ventilate a sound deadening casing by any means whatever.

Other features and advantages of this invention will hereinafter appear.

In the accompanying drawings;

Figure 1 is a cross-sectional view in elevation showing the device mounted on the diaphragm box of a standard telephone transmitter.

Figure 2 is a plan view, partly in crosssection, and shows the doors in operating or closed positions.

Figure 3 is a similar view. showing the doors in open or ventilating positions.

Figure 4 is a cross-sectional View through line H of Figure 2.

Figure 5 is a perspective view of the device mounted on the telephone transmitter.

Figure 6 is a cross-sectional view through line 66 of Figure 2.

In the form selected to better illustrate the present invent-ion, the device consists of a sound deadening casing having an upper double wall 10 and a lower double wallll both walls being secured to a square back plate 12, and to a front plate 13. The back plate is provided with a hole for receiving a mouth-piece l i carried by a diaphragm box of av telephone transmitter indicatedgen- I erally by thenumeral 16. The platel2-is securedto aclamping piece 17 which engages,

,by me ans gof prongs 18, the outer edge'of a ,lates to,.mea ns for ventilating the-sound} .gdeadcning ,casing, when .not in use, to; the,

diaphragnr front plate 19. This arrangement renders the ,casing easily detachable from the transmitter and may be manufactured and sold as a separate unit, independently of the telephone.

In order that a sound proof joint may be provided between the clamping member 17 andthe diaphragm plate 19 there is provided a ring 20 of rubber, felt or similar material.

"This ring may be forced into a recess formed at-the inner edge of the clamping plate 17.

The front plate 13 has a hole therein which is provided with an edge 21 bent outwardly and designed to receive a mouth-piece formed by an inner wall 22 and an outer wall 23. The outer edge 24 of the mouthpiece is smooth and is shaped to conform with the lips of the speaker which serve as an effective closure to prevent emission of sound through the opening formed by the mouth-piece.

The sides of the casing are normally open as shown in Figure 3 so as to ventilate the interior thereof, but may be closed when the device is to be used by means of swiveled doors 25 and 26. The rear doors 26 are pivotally mounted on a rod 27 which is secured to the inner plates 28 of the upper and lower walls 10 and 11. The doors 25 are hinged on the free ends of the doors 26 by means of rods 29 which protrude through guiding slots 30 and are engaged by operating arms 31 under the control of a handle or finger piece 32. The arms 31 are provided with elongated slots 33 and are pivotally mounted by means of studs 34 and 35 between the plates of the lower wall 11. The stud 34 extends downwardly and carries, fast thereto, the finger piece 32. In order that both arms 31 may be concomitantly operated it is contrived to provide the arms with geared sectors having teeth 36 engaging with each other as shown in Figures 2 and 3. The free ends of the doors 25 are provided with pins 38 designed to slide in guiding slots 39 in the plate 28.

It will be understood that instead of providing the casing with side doors, the same could be provided with a'single door at the top thereof. In this case the door could be operated by a single finger piece mounted at the end of a supporting shaft. The door could be made double, as in the form shown to illustrate this invention, thus further preventing the emission of sound through the walls to the exterior of the casing. The eflect of a double wall is well knownin the art.

Variations may be resorted to within the scope of the invention, and portions of the improvement may be used without others.

Having thus described my invention, 1 claim: 7

1; A sound deadening casing for a telephone transmitter having apertures at opposite sides thereof for permitting circulation of air therethrough, and manual means for concomitantly closing said apertures at will. g

2. A sound deadening casingztor atelephone transmitter having doors at the sides 7 thereof for ventilating the interior of the o enin and closin said doors. said means casing, and. manually controllable means for including a pair of pivotally mounted geared sectors for engaging said doors and a handle for operatingone of the sectors.

phone transmitter, said casing including a rigid frame, a mouth piece on said frame, means forattaohlng said frame to the diap'hragm casing of the telephone transmitter,

a pair of full sized doors at opposite sides ofthe casing, said doors serving as sound deadening walls when the apparatus is in use but being concomitantly operable to .be opened at will so as to permit a current of air to circulate through'the interior of the casing. V

4:. A sound deadening casing for a telephone transmitter, said casing including upper and lower walls, a front wall having a mouthpiece attached thereto, arear wall ALBERT SCHWARTZ.

3. A sound deadening casing for a tele- 

